Process for preparing fluorochemical monoisocyanates

ABSTRACT

A process for preparing fluorochemical monoisocyanates comprises reacting at least one fluorochemical alcohol represented by the formula C n F 2n+1 SO 2 NCH 3 (CH 2 ) m OH, wherein n=2 to 5, and m=2 to 4, with 4,4′-diphenylmethane diisocyanate (MDI) in a solvent in which the resulting fluorochemical monoisocyanate is not soluble; wherein the molar ratio of fluorochemical alcohol:MDI is from about 1:1 to about 1:2.5.

This application is a divisional of U.S. Ser. No. 10/751,142, filed Dec.31, 2003, now allowed, the disclosure of which is herein incorporated byreference.

FIELD

This invention relates to a process for selectively preparingfluorochemical monoisocyanates.

BACKGROUND

Various fluorinated acrylic resins containing urethane linkages areknown to have water- and oil-repellency properties (see, for example,U.S. Pat. No. 4,321,404 (Williams et al.), U.S. Pat. No. 4,778,915 (Linaet al.), U.S. Pat. No. 4,920,190 (Lina et al.), U.S. Pat. No. 5,144,056(Anton et al.), and U.S. Pat. No. 5,446,118 (Shen et al.)). These resinscan be polymerized and applied as coatings to substrates such as, forexample, textiles, carpets, wall coverings, leather, and the like toimpart water- and oil repellency.

Typically, these resins comprise long chain pendant perfluorinatedgroups (for example, 8 carbon atoms or greater) because long chainsreadily align parallel to adjacent pendant groups attached to acrylicbackbone units, and thus maximize water- and oil-repellency. However,long chain perfluorinated group-containing compounds such as, forexample, perfluorooctyl containing compounds may bioaccumulate in livingorganisms (see, for example, U.S. Pat. No. 5,688,884 (Baker et al.)).

SUMMARY

In view of the foregoing, we recognize that there is a need forpolymerizable water- and oil-repellent acrylic resins that are lessbioaccumulative. Furthermore, in order for such compounds to becommercially attractive, we recognize that there is a need for aneconomical process for preparing starting compounds useful in theirpreparation.

Briefly, in one aspect, the present invention provides a process forpreparing fluorochemical monoisocyanates that have short chainperfluorinated groups, which are thought to be less toxic and lessbioaccumulative than longer chain perfluorinated groups (see, forexample, WO 01/30873). These fluorochemical monoisocyanates can bereacted with acrylates, and then polymerized, to provide polymers havingoil- and water-repellency properties.

The process of the invention comprises reacting at least onefluorochemical alcohol represented by the formulaC_(n)F_(2n+1)SO₂NCH₃(CH₂)_(m)OH, wherein n=2 to 5, and m=2 to 4, with4,4′-diphenylmethane diisocyanate (MDI) in a solvent in which theresulting fluorochemical monoisocyanate is not soluble; wherein themolar ratio of fluorochemical alcohol:MDI is from about 1:1 to about1:2.5.

Surprisingly, it has been discovered that the process of the inventioncan be used to selectively prepare fluorochemical monoisocyanates inpurities greater than 85% without any further purification. Furthermore,the process can be carried out using a substantially smaller excess ofdiisocyanate than other known processes (see, for example, U.S. Pat. No.5,446,118 (Shen et al.), and U.S. Patent App. No. US 2001/0005738 A1(Bruchmann et al.)).

The process of the invention therefore meets the need in the art for aneconomical process for preparing starting compounds useful in thepreparation of less bioaccumulative polymerizable water- andoil-repellent acrylic resins.

In another aspect, this invention also provides fluorochemicalisocyanate compositions prepared by the process of the invention whereinsaid composition comprises greater than about 85% monoisocyanate.

DETAILED DESCRIPTION

Fluorochemical alcohols that are useful in carrying out the process ofthe invention include those represented by the following formula:C_(n)F_(2n+1)SO₂NCH₃(CH₂)_(m)OHwherein n=2 to 5, and m=2 to 4 (preferably, n=2 to 4; more preferably,n=4).

Fluorochemical alcohols that are useful starting compounds includeC₂F₅SO₂NCH₃(CH₂)₂OH, C₂F₅SO₂NCH₃(CH₂)₃OH, C₂F₅SO₂NCH₃(CH₂)₄OH,C₃F₇SO₂NCH₃(CH₂)₂OH, C₃F₇SO₂NCH₃(CH₂)₃OH, C₃F₇SO₂NCH₃(CH₂)₄OH,C₄F₉SO₂NCH₃(CH₂)₂OH, C₄F₉SO₂NCH₃(CH₂)₃OH, C₄F₉SO₂NCH₃(CH₂)₄OH,C₅F₁₁SO₂NCH₃(CH₂)₂OH, C₅F₁₁SO₂NCH₃ (CH₂)₃OH, C₅F₁₁SO₂NCH₃(CH₂)₄OH, andmixtures thereof. Preferred fluorochemical alcohols include, forexample, C₂F₅SO₂NCH₃(CH₂)₂OH, C₄F₉SO₂NCH₃(CH₂)₂OH, C₄F₉SO₂NCH₃(CH₂)₄OH,and mixtures thereof. More preferred fluorochemical alcohols include,for example, C₄F₉SO₂NCH₃(CH₂)₂OH, C₄F₉SO₂NCH₃(CH₂)₄OH, and mixturesthereof. A most preferred fluorochemical alcohol is C₄F₉SO₂NCH₃(CH₂)₂OH.

Useful fluorochemical alcohols can be purchased from 3M (St. Paul,Minn.), or can be prepared essentially as described in U.S. Pat. No.2,803,656 (Ahlbrecht et al.) and U.S. Pat. No. 6,664,345 (Savu et al.).

The above-described fluorochemical alcohols can be reacted with4,4′-diphenylmethane diisocyanate in a solvent to form the correspondingmonoisocyanates. 4,4′-Diphenylmethane diisocyanate is commonly known as“methylene diisocyanate” or “MDI”. In its pure form, MDI is commerciallyavailable as Isonate™60 125M from the Dow Chemical Company (Midland,Mich.), and as Mondur™ M from Bayer Polymers (Pittsburgh, Pa.).

The process of the invention can be carried out with a molar ratio offluorochemical alcohol:MDI from about 1:1 to about 1:2.5. Preferably,the molar ratio of fluorochemical alcohol:MDI is from about 1:1 to about1:2. More preferably, the molar ratio is from about 1:1.1 to about1:1.5.

The process of the invention can be carried out in a solvent in whichthe resulting monoisocyanate is not soluble (that is, the solvent is onein which the monoisocyanate partitions out of so that it no longerparticipates in the reaction). Preferably, the solvent is a nonpolarsolvent. More preferably, it is a nonpolar non-aromatic hydrocarbon orhalogenated solvent.

Representative examples of useful solvents include cyclohexane,n-heptane, hexanes, n-hexane, pentane, n-decane, i-octane, octane,methyl nonafluoroisobutyl ether, methyl nonafluorobutyl ether, petroleumether, and the like, and mixtures thereof. A mixture of methylnonafluoroisobutyl ether and methyl nonafluorobutyl ether is availableas HFE-7100 Novec™ Engineered Fluid from 3M (St. Paul, Minn.). Preferredsolvents include, for example, methyl nonafluoroisobutyl ether, methylnonafluorobutyl ether, petroleum ether, n-heptane, and the like.

Preferably, the solvent has a Hildebrand solubility parameter (δ) ofless than about 8.3 (cal/cm³)^(1/2) (about 17 MPa^(1/2)) and a hydrogenbonding index of less than about 4.

The Hildebrand solubility parameter is a numerical value that indicatesthe relative solvency behavior of a specific solvent. It is derived fromthe cohesive energy density (c) of the solvent, which in turn is derivedfrom the heat of vaporization:$\delta = {\sqrt{c} = \left\lbrack \frac{{\Delta\quad H} - {RT}}{V_{m}} \right\rbrack^{1/2}}$

wherein:

ΔH=heat of vaporization,

R=gas constant,

T=temperature, and

V_(m)=molar volume

For example, n-heptane has a Hildebrand solubility index of about 7.4(cal/cm³)^(1/2) (about 15 MPa^(1/2)), and water has a Hildebrandsolubility index of about 23.4 (cal/cm³)^(1/2) (about 48 MPa^(1/2))(Principles of Polymer Systems, 2^(nd) edition, McGraw-Hill BookCompany, New York (1982)).

The hydrogen bonding index is a numerical value that indicates thestrength of the hydrogen bonding that occurs in a solvent. Hydrogenbonding values range from −18 to +15. For example, n-heptane has ahydrogen bonding value of about 2.2, and water has a hydrogen bondingvalue of about 16.2 (Principles of Polymer Systems, 2^(nd) edition,McGraw-Hill Book Company, New York (1982)).

The reaction can be carried out by combining the fluorochemical alcoholand MDI in the solvent. Preferably, the fluorochemical alcohol is addedto MDI, which is in the solvent, over time. Optionally, thefluorochemical alcohol can first be dissolved in a solvent such as, forexample, toluene, and then added to the MDI in solution. Preferably, thereaction mixture is agitated. The reaction can generally be carried outat a temperature between about 25° C. and about 70° C. (preferably,between about 25° C. and about 50° C.).

Optionally, the reaction can be carried out in the presence of acatalyst. Useful catalysts include bases (for example, tertiary amines,alkoxides, and carboxylates), metal salts and chelates, organometalliccompounds, acids, and urethanes. Preferably, the catalyst is anorganotin compound (for example, dibutyltin dilaurate (DBTDL)) or atertiary amine (for example, diazobicyclo[2.2.2]octane (DABCO)), or acombination thereof. More preferably, the catalyst is DBTDL.

After the reaction is carried out, the reaction product can be filteredout and dried. The reaction product typically comprises greater thanabout 85% of the desired fluorochemical monoisocyanate (preferably,greater than about 90%; more preferably, greater than about 95%).

Fluorochemical monoisocyanates that can be prepared using the process ofthe invention can be represented by the following formula:

wherein n=2 to 5, and m=2 to 4.

Preferred fluorochemical monoisocyanates that can be prepared using theprocess of the invention include, for example:

More preferred fluorochemical monoisocyanates prepared using the processof the invention include, for example:

Fluorochemical monoisocyanates prepared using the process of theinvention can be useful starting compounds in processes for preparingfluorinated acrylic polymers with water- and oil-repellency properties.

For example, fluorochemical monoisocyanates prepared using the processof the invention can be reacted with active hydrogen-containingcompounds, materials, or surfaces bearing hydroxyl, primary or secondaryamines, or thiol groups. The monomer produced by reacting afluorochemical monoisocyanate prepared by the process of the inventionwith a hydroxy alkyl acrylate such as hydroxy ethyl acrylate, forexample, can be polymerized (alone or with comonomers) to providepolymers that have useful water- and oil-repellency properties.

EXAMPLES

Objects and advantages of this invention are further illustrated by thefollowing examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this invention. Name, Formulaand/or Designator Structure Availability BICMCH 1,3 Bis- Sigma-Aldrich,isocyanatomethyl Milwaukee, WI cyclohexane DBTDL Dibutyltin dilaurateSigma-Aldrich Fluowet EA 600 C₆F₁₃CH₂CH₂OH Clariant Corp. HDI1,6-Diisocyanatohexane Sigma-Aldrich HFE-7100 C₄F₉OCH₃ 3M Company, St.Paul, MN H12MDI DESMODUR ™ W; 1,1′- Bayer Polymers Methylenebis-(4- LLC,Pittsburgh, isocyanatocyclohexane) PA MDI MONDUR ™ M; 1,1′- BayerPolymers Methylenebis-(4- LLC isocyanatobenzene) MeFBSEC₄F₉SO₂N(CH₃)CH₂CH₂OH 3M Company MTBE Methyl-t-butyl ether; MallinckrodtCH₃OC(CH₃)₃ Baker, Inc., Phillipsburg, NJ Petroleum ether MallinckrodtBaker, Inc. PDI 1,4-Phenylene Sigma-Aldrich diisocyanate TDI Tolylene2,4- Sigma-Aldrich disocyanate TMDI Trimethyl-1,6- Bayer Polymersdiisocyanatohexane LLC TMXDI m-Tetramethylxylene Cytec Industries,diisocyanate West Patterson, NJ Toluene C₆H₅CH₃ Mallinckrodt Baker, Inc.C₄F₉SO₂N(CH₃)H 3M Company C₂F₅SO₂F 3M Company C₄F₉CH₂CH₂OH TCI America,Portland, ORPreparation of C₄F₉SO₂N(CH₃)(CH₂)₄OH

To a mixture of 64.8 g 25% NaOCH₃ in CH₃OH (available from Aldrich), 100ml CH₃OH, and 100 ml diglyme was added 93.9 g C₄F₉SO₂NH(CH₃). Themixture was then stripped at 60° C./20 mTorr to 190.0 g. The strippedmixture was transferred to a paddle-stirred reaction flask using 125 mLdiglyme, heated at 100° C. for 10 min (without a condenser) to removetraces of CH₃OH, and then treated with 75 g 4-chlorobutyl acetate(available from Aldrich). The resulting slurry was heated for 6 hr at136° C., treated with 15 g of CH₂Cl₂, and heated for an additional 20 hrat 136° C. The resulting mixture was then washed with water, extractedwith CH₂Cl₂, stripped to 237.8 g, and distilled (1-plate) to yield a75.1 g main cut at 110-130° C./0.2-0.3 mTorr. The resulting material,C₄F₉SO₂NCH₃C₄H₈ acetate, was dissolved in 50 mL ethanol and treated with5.0 g 50% NaOH diluted with 20 mL water with agitation. After 24 hr,infrared spectroscopy (IR) showed no acetate remaining. The product wasextracted with CH₂Cl₂ to yield 65.7 g C₄F₉SO₂NCH₃C₄H₈OH, a pale tanliquid.

Preparation of C₄F₉SO₂N(CH₃)(CH₂)₁₁OH

C₄F₉SO₂N(CH₃)(CH₂)₁₁OH was prepared using a procedure similar to thatdescribed above for preparing C₄F₉SO₂N(CH₃)(CH₂)₄OH. 175.9 gC₄F₉SO₂NHCH₃ and 121.4 g 25% NaOCH₃ were reacted to produce a solutionof C₄F₉SO₂NNaCH₃ in about 100 mL diglyme. This solution was treated with141 g 11-bromoundecanol (available from Aldrich) and heated at 100° C.for 20 hr to form a heavy precipitate. The reaction was quenched inabout 600 mL warm water and the resulting lower layer was stripped at50° C./0.5 mTorr to leave 269.9 g of C₄F₉SO₂N(CH₃)(CH₂)₁₁OH, alow-melting solid.

Preparation of C₂F₅SO₂N(CH₃)CH₂CH₂OH

C₂F₅SO₂N(CH₃)CH₂CH₂OH can be prepared essentially as described inExample 1 Part A and Example 2 Part A of U.S. Pat. No. 6,664,354 (Savuet al.) with the exception that an equimolar amount of C₂F₅SO₂F issubstituted for C₄F₉SO₂F.

C₂F₅SO₂N(CH₃)CH₂CH₂OH was prepared from C₂F₅SO₂F by reaction withmonomethylamine in MTBE, followed by stripping of the solvent,acidification with 19% sulfuric acid, then water washing anddistillation at 5.5 mm at a head temperature of 69° C. to giveC₂F₅SO₂N(CH₃)H. The C₂F₅SO₂N(CH₃)H was then reacted with 3 equivalentsof ethylene carbonate and 0.08 equivalents K₂CO₃ neat at 110° C.overnight. The product was isolated by successive washes with water, 3%sulfuric acid and water, followed by distillation at 0.5 mm at a headtemperature of 98° C.

Example 1 Reaction of C₄F₉SO₂N(CH₃)(CH₂)₄OH with MDI: 1.0:1.5

To a flask containing 37.5 g (0.15 mol) MDI in 75 g heptane (filtered at50° C. through a C porosity frit), was added two drops of DBTDL at 50°C. and 38.5 g C₄F₉SO₂N(CH₃)(CH₂)₄OH in 10 g heptane over 35 min. Afterreaction overnight at 50° C., the resulting solid was filtered, rinsedwith heptane, and sucked dry under nitrogen to provide 69.67 g of awhite powder that was 75.5% solids.

Example 2 Reaction of C₂F₅SO₂N(CH₃)(CH₂)₂OH with MDI: 1.0:1.5

To a flask containing 37.5 g (0.15 mol) MDI in 75 g heptane (filtered at50° C. through a C porosity frit), and two drops of DBTDL at 50° C. wasadded 25.7 g (0.10 mol) C₂F₅SO₂N(CH₃)(CH₂)₂OH dropwise over 58 min. At3.5 h, the resulting solid was filtered, rinsed with 120 g heptane, andsucked dry under nitrogen to provide 69.43 g of a white powder that was71% solids, the remainder being heptane. (49.29 g yield, 97.2%)

Example 3 Reaction of MeFBSE with MDI: 1:1.1

To a 3 liter Morton flask was added 900 ml of dry heptane, followed by283.4 g (1.1 mol) of fresh MDI. Stirring was be gun as heat was applied.Added 4 drops of DBTDL. When the temperature of the solution reached 45°C., 357.2 g (1 mol) of MeFBSE was added in 5 portions, over a 1 hourperiod. Within 2 minutes, the product began separating as a finelydivided, granular solid. The reaction was slightly exothermic(approximately 3 degrees Centigrade). When the addition of the MeFBSEwas completed, the reaction was continued for another 1.5 hours attemperature. The reaction contents were then filtered under anatmosphere of nitrogen, and returned to the flask. An additional volumeof heptane was added, and the solid was stirred for 15 minutes at 45°C., then filtered and rinsed with an additional volume of heptane undera nitrogen atmosphere. The resulting granular white solid wastransferred to a large glass container, then flushed with nitrogen untilthe solvent was removed. (Alternatively, the solid could have beenvacuum dried at 45° C. until the solvent was removed.) Approximately 588g of product was isolated (97% yield).

Example 4 Reaction of MeFBSE with MDI: 1:1.2

Example 4 was prepared by essentially following the procedure describedfor Example 3, with the exception that the molar ratio of MeFBSE:MDI was1:1.2.

Example 5 Reaction of MeFBSE with MDI: 1:1.3

Example 5 was prepared by essentially following the procedure describedfor Example 3, with the exception that the molar ratio of MeFBSE:MDI was1:1.3.

Example 6 Reaction of MeFBSE with MDI: 1:1.4

Example 6 was prepared by essentially following the procedure describedfor Example 3, with the exception that the molar ratio of MeFBSE:MDI was1:1.4.

Example 7 Reaction of MeFBSE with MDI: 1:1.5

Example 7 was prepared by essentially following the procedure describedfor Example 3, with the exception that the molar ratio of MeFBSE:MDI was1:1.5.

Example 8 Reaction of MeFBSE with MDI: 1:2

Example 8 was prepared by essentially following the procedure describedfor Example 3, with the exception that the molar ratio of MeFBSE:MDI was1:2.

Example 9 Reaction of MeFBSE with MDI: 1.0:2.5

Example 9 was prepared by essentially following the procedure describedfor Example 3, with the exception that the molar ratio of MeFBSE:MDI was1.0:2.5

Example 10 Reaction of MeFBSE with MDI: 1:1.3 (Heptane/toluene Solvent)

To a 1 liter, 3 necked, round bottomed flask equipped with a paddlestirrer, thermometer with temperature controller, and powder additionfunnel, was added 45.6 g (0.18 mol) of MDI followed by 300 g of dryheptane, and 3 drops of DBTDL, under a nitrogen atmosphere. Stirring wasbegun and the temperature was raised to 45° C. To this clear solutionwas added, over 45-60 minutes, a solution of MeFBSE (150 ml toluene),which was azeotroped to remove traces of water. The MeFBSE solution wasplaced in a pressure equalized dropping funnel, and needed occasionalheating to keep the MeFBSE in solution. As the reaction proceeded, asolid product precipitated. After the addition of the MeFBSE wascompleted, the reaction was continued at 45° C. for an additional 1.5hours. It was filtered warm, rinsed with an equivalent volume of warmheptane, and then dried under an atmosphere of nitrogen.

Example 11 Reaction of MeFBSE with MDI: 1:1.3 (Petroleum Ether Solvent)

Example 11 was prepared essentially following the procedure described inExample 5, except substituting 400 ml of petroleum ether for theheptane. The product immediately precipitated as MeFBSE was added. TheMeFBSE was added over a 1 hour period. The product was isolated after a1.5 hour hold period, and rinsed once with warm petroleum ether, thendried with nitrogen. The yield was 82 g.

Example 12 Reaction of MeFBSE with MDI: 1:1.3 (HFE-7100 Solvent)

Example 12 was prepared essentially following the procedure described inExample 5, except substituting 300 ml of HFE-7100 for heptane. The MDIwas not soluble to any large extent in this solvent. The productimmediately precipitated. The product was rinsed with warm heptane ofequal volume, and dried by nitrogen stream.

Comparative Example C-1 Reaction of C₄F₉SO₂N(CH₃)(CH₂)₁₁OH with MDI:1.0:1.5

A solution of 28.13 g (0.1125 mol) MDI in 65 g heptane at 50° C. wasfiltered into a 250 ml 3-necked round bottom flask and two drops ofDBTDL were added to the flask. To this reaction mixture at 35° C. wasadded 4 roughly equal portions, 36.23 (0.075 mole)C₄F₉SO₂N(CH₃)(CH₂)₁₁OH at t=0, 15, 30, and 45 min. After 3 h, thereaction was heated to 40° C. and the upper heptane phase was decantedfrom a solid product. Next, 65 g heptane was added and the reaction washeated to 70° C. After the solid became molten, the reaction was allowedto cool overnight to room temperature and the heptane layer was decantedoff. Then, heptane (65 g) was added to the reaction, which was heated to70° C. After stirring, the heptane layer was decanted off, leaving 52 gof a thick whitish solid.

Comparative Example C-2 Reaction of FLUOWET EA 600 with MDI: 1.5:1.0

A 3 neck 250 mL round bottom flask equipped with thermometer andoverhead stirrer, was charged with 35.4 g (0.15 mole) MDI and 75 gheptane. The contents were heated to 50° C., and 2 drops of DBTDL wereadded. Next, 36.4 g (0.10 mol) FLUOWET EA 600 was added over 1 h viadropping funnel under nitrogen. Within 5 minutes a precipitate wasevident. The reaction was run overnight, then diluted with 15 g heptaneand vacuum filtered through filter paper under a stream of nitrogen. Thefilter cake was washed with 4 portions (totaling 50 g) of heptane at 50°C. The material was dried in a vacuum oven with a nitrogen bleed at 60°C. overnight to yield 53.66 g of a white powder.

Comparative Example C-3 Reaction of C₄F₉CH₂CH₂OH with MDI: 1.0:1.5

In a manner essentially as described in Comparative Example C-2, 14.19 g(0.0568 mol) MDI in 30 g heptane was reacted with 10.0 g (0.0379 mol) ofC₄F₉CH₂CH₂OH to provide a solid that was filtered, but not dried.

Comparative Example C-4 Reaction of MDI with Trifluoroethanol, 1.5:1.0

To a 1 liter, 3 necked, round bottomed flask equipped with a paddlestirrer, thermometer with temperature controller, and pressure equalizedliquid addition funnel, was added 125.3 g (0.50 mol) of MDI, followed by400 g of dry heptane, and 3 drops of DBTDL, under a nitrogen atmosphere.Stirring was begun and the temperature was raised to 55° C. To thissolution was added, portion-wise over 1 hour, 33.3 g (0.33 mol) oftrifluoroethanol. A white solid immediately precipitated from thereaction, and the contents took on a thick, pasty consistency. Thereaction was run overnight at 55° C. It was then filtered warm andrinsed with an additional volume of heptane, and vacuum dried at 45° C.overnight. About 100 g of a white solid was recovered.

Comparative Example C-5 Reaction of MeFBSE with MDI: 1:1.3 (MTBESolvent)

Comparative Example C-5 was prepared essentially following the proceduredescribed in Example 5, except substituting 300 ml of MTBE for heptane.Much of the product does not precipitate in the MTBE. The solid wasrinsed once with an equivalent volume of warm heptane.

Comparative Example C-6 Reaction of MDI with n-Octanol: 3.5:1

To a 1 liter, 3 necked, round bottomed flask equipped with a paddlestirrer, thermometer with temperature controller, and pressure equalizedliquid addition funnel, was added 166.7 g (0.42 mol) of MDI followed by400 g of dry heptane, and 3 drops of DBTDL, under a nitrogen atmosphere.Stirring was begun and the temperature was raised to 55° C. To thissolution was added, portion-wise over 1 hour, 43.4 g (0.12 mol) ofn-octanol. The reaction contents remained homogeneous, for the mostpart, at this temperature. The reaction was run overnight at 55° C. Uponcooling to room temperature, a white solid precipitated. The white solidwas filtered, rinsed with room temperature heptane, pulled dry on thefunnel under an atmosphere of nitrogen, and then dried overnight in a45° C. vacuum oven. About 100 g of a white solid was recovered.

Comparative Example C-7 Reaction of MeFBSE with MDI: 1:1.3 (TolueneSolvent)

To a 1 liter, 3 necked, round bottomed flask equipped with a paddlestirrer, thermometer with temperature controller, and powder additionfunnel, was added 45.6 g (0.18 mol) of MDI followed by 400 g of drytoluene, and 3 drops of DBTDL, under a nitrogen atmosphere. Stirring wasbegun and the temperature was raised to 45° C. To this clear solutionwas added, portion wise over 2 minutes, 50 g (0.14 mol) of MeFBSE. Thecontents were completely in solution. Shortly thereafter, a solid beganto precipitate. Heating was continued for 1.5 hours more, then thereaction mixture was allowed to stir at room temperature overnight.Approximately 200 ml of heptane was warmed to around 50° C. and used torinse the solid as it was filtered under an atmosphere of nitrogen. Thewhite solid was pulled dry with the nitrogen stream, then transferred toa glass jar. Approximately 73 g of a white, free-flowing powder wasrecovered.

Comparative Example C-8 Reaction of C₄F₉SO₂N(CH₃)CH₂CH₂OH with TMXDI:1.0:1.5

In a manner essentially as described in Comparative Example C-13, 36.65g (0.15 mol) TMXDI was reacted with 35.7 (0.1 mole) moltenC₄F₉SO₂N(CH₃)CH₂CH₂OH. After reaction overnight, the solids werefiltered and washed with heptane to provide 39.4 of a heptane wet solid.

Comparative Example C-9 Reaction of MeFBSE with TDI: 1.0:1.5

To a flask containing 26.2 g (0.15 mol) TDI, 65 g heptane, and two dropsof DBTDL at 22° C., was added 35.7 g (0.10 mol) C₄F₉SO₂N(CH₃)CH₂CH₂OH infour equal portions at t=0, 12, 24, and 36 min, with the temperaturerising to 33° C. After 6 h of reaction the resulting solid was filtered,rinsed with heptane, and sucked dry under nitrogen to provide 60.98 g ofa white free-flowing powder.

Comparative Example C-10 Reaction of MeFBSE with HDI: 1:2

To a 1 liter, 3 necked, round bottomed flask equipped with a paddlestirrer, thermometer with temperature controller, and powder additionfunnel, was added 112 g (0.66 mol) of HDI followed by 350 g of dryheptane, and 3 drops of DBTDL, under a nitrogen atmosphere. Stirring wasbegun and the temperature was raised to 55° C. To this clear solutionwas added, portion-wise over 1.5 hours, 119 g (0.33 mol) of MeFBSE.Within 10 minutes of the beginning of MeFBSE addition, a white solidbegan precipitating from the reaction contents. The reaction wascontinued at 55° C. overnight. A larger volume of white solid formed,and was filtered under a nitrogen atmosphere, at room temperature.Residue in the flask was rinsed out with an additional 300 g of dryheptane. The recovered solid was dried in a vacuum oven at 45° C., usinga drying tower of CaCl₂. This solid partially melted during the dryingprocess. The yield was approximately 160 g.

Comparative Example C-11 Reaction of MeFBSE with TMDI: 1.0:1.5

To a 1 liter, 3 necked, round bottomed flask equipped with a paddlestirrer, thermometer with temperature controller, and powder additionfunnel, was added 88.4 g (0.42 mol) of TMDI followed by 400 g of dryhexane, and 3 drops of DBTDL, under a nitrogen atmosphere. Stirring wasbegun and the temperature was raised to 55° C. To this clear solutionwas added, portion-wise over 2 hours, 100 g (0.28 mol) of MeFBSE. Mostof the solid settled to the bottom of the flask, but as it reacted, thecontents clarified. The reaction was continued at 55° C. for anotherhour, then kept at room temperature, overnight. A large volume of whitesolid was present. More hexane was added (about 100 g) to the contentsof the flask, then it was chilled with an ice bath, and filtered under astream of nitrogen. The solid appeared to be free-flowing, but uponvacuum drying overnight at 45° C., it coalesced to form a waxy solid.

Comparative Example C-12 Reaction of MeFBSE with PDI 1.0:1.5

To a 1 liter, 3 necked, round bottomed flask equipped with a paddlestirrer, thermometer with temperature controller, and powder additionfunnel, was added 67.3 g (0.42 mol) of PDI followed by 400 g of dryheptane, and 3 drops of DBTDL, under a nitrogen atmosphere. The PDI hadvery little solubility in heptane. Stirring was begun and thetemperature was raised to 55° C. To this slurry was added, portion-wiseover 2 hours, 100 g (0.28 mol) of MeFBSE. Product formed almostimmediately upon reaction with the MeFBSE. An additional 100 g ofheptane was added, to aid in stirring. The reaction contents werefiltered after an additional 2 hours of stirring at 55° C., and thenrinsed with an equivalent volume of warm heptane. The resulting solidwas transferred to an Erlenmeyer flask and heated with another volume ofheptane, then filtered, under a nitrogen atmosphere. Additional heptanewas used for rinsing. The solid was dried in a vacuum oven at 45° C.overnight. About 135 g of a light, powdery solid was recovered.

Comparative Example C-13 Reaction of C₄F₉SO₂N(CH₃)CH₂CH₂OH with H12MDI:1.0:1.5

In a manner essentially as described above, 39.3 g (0.15 mol) MDI wasreacted with 0.10 mole of molten C₄F₉SO₂N(CH₃)CH₂CH₂OH at about 90-100°C., which was delivered at a constant rate over 72 min from a droppingfunnel wrapped with heating tape. After several hours, the reaction wasallowed to cool to room temperature. The upper liquid phase was decantedoff. The lower whitish phase was heated to 50° C., at which point itmelted. It was then slurried with 50 g of heptane at 50° C. for 15 min,and the upper liquid phase was decanted off. Next, the solid was mixedat room temperature with heptane (60 g) and was vacuum filtered to yield46.5 g of a free-flowing powder.

Comparative Example C-14 Reaction of MeFBSE with BICMCH: 1:1.5

To a 1 liter, 3 necked, round bottomed flask equipped with a paddlestirrer, thermometer with temperature controller, and powder additionfunnel, was added 100.1 g (0.52 mol) of BICMCH, followed by 350 g of dryhexane, and 3 drops of DBTDL, under a nitrogen atmosphere. Stirring wasbegun and the temperature was raised to 55° C. To this clear solutionwas added, portion-wise over 1.5 hours, 122 g (0.341 mol) of MeFBSE.Within 10 minutes of the beginning of MeFBSE addition, an oil beganseparating from the reaction contents. The reaction was continued atroom temperature, overnight. A waxy solid formed. The solvent layer wasdecanted and discarded. It was replaced with fresh hexane, and themixture was heated to 55° C. with stirring. The solvent layer wasdecanted and discarded again. This was repeated an additional time, thenthe mixture was cooled to room temperature. The contents remained a waxysolid. The waxy solid was removed, then broken up into smaller pieces,and kept under a stream of nitrogen. The product had good solubility inacetone.

Sample Analysis:

All samples were prepared by weighing 20 to 25 mg of sample in a vial,immediately adding 100 μL of anhydrous methanol, and then 250 μL ofanhydrous dimethyl sulfoxide (DMSO) to dissolve the sample. To thissolution, 1 mL of MTBE containing a small amount of DBTL (2 drops in 10mL MTBE) was added. The vial was heated at 50° C. for 20 minutes. Thesample was cooled to room temperature, and the MTBE was removed byblowing a stream of nitrogen over the solution for 10 minutes. Twohundred and fifty μL of DMSO was added to the sample followed by 15 mLof acetonitrile. The sample solutions were each analyzed by highperformance liquid chromatography (HPLC) under the followingchromatographic conditions:

Instrument: Agilent 1100 HPLC

Column: Merck Purospher RP18e, 5 μm, 125×3 mm

Solvent A: Water

Solvent B: Acetonitrile

Gradient: 40% B to 100% B in 15 minutes and hold 100% B for 10 minutes

Flow Rate: 0.5 mL/min

Injection: 2 μL

Detector: UV at 254 nm

The methanolized samples were further analyzed by liquidchromatogrphy-mass spectrometry (LC-MS) in positive electrosprayionization in order to identify the major components that were observedin the HPLC chromatograms.

Data is reported in Table 1 as UV Area (%) of the desired monoisocyanateproduct. TABLE 1 UV Area (%) of Monoisocyanate UV Area UV Area Example(%) Example (%) 1 89.12 C-1 20.12 2 85.89 C-2 61.60 3 93.18 C-3 78.53 495.34 C-4 65.09 5 94.69 C-5 14.69 6 94.23 C-6 82.37 7 92.88 C-7 70.95 894.22 C-8 19.66 9 85.37 C-9 83.98 10 93.94 C-10 66.70 11 96.50 C-1115.31 12 90.04 C-12 69.59 C-13 54.14 C-14 40.63

The referenced descriptions contained in the patents, patent documents,and publications cited herein are incorporated by reference in theirentirety as if each were individually incorporated.

Various modifications and alterations to this invention will becomeapparent to those skilled in the art without departing from the scopeand spirit of this invention. It should be understood that thisinvention is not intended to be unduly limited by the illustrativeembodiments and examples set forth herein and that such examples andembodiments are presented by way of example only with the scope of theinvention intended to be limited only by the claims set forth herein asfollows.

1. A process for preparing fluorochemical monoisocyanates comprisingreacting at least one fluorochemical alcohol represented by the formulaC_(n)F_(2n+1)SO₂NCH₃(CH₂)_(m)OH, wherein n=2 to 5, and m=2 to 4, with4,4′-diphenylmethane diisocyanate (MDI) in a solvent in which theresulting fluorochemical monoisocyanate is not soluble; wherein themolar ratio of fluorochemical alcohol:MDI is from about 1:1 to about1:2.5.
 2. A fluorochemical isocyanate composition prepared by theprocess of claim 1 wherein said composition comprises greater than about85% monoisocyanate.
 3. The fluorochemical isocyanate composition ofclaim 2 wherein said composition comprises greater than about 90%monoisocyanate.
 4. The fluorochemical isocyanate composition of claim 3wherein said composition comprises greater than about 95%monoisocyanate.